Innovative asphalt surface layers to reduce traffic noise

From 2005 to 2010 the joint research project ‘Quiet Road Traffic 2’ was carried out with partners from industry, universities and other research institutes. A main topic was the further improvement of surface layers made of Porous Asphalt (PA). A conventional composition of PA reaches a limit in noise reduction which makes new approaches necessary. For this purpose Helmholtz-Resonators were used to control the absorption of PA. A second important research topic was the improvement of the acoustic durability by reducing the clogging process of the voids. Hopefully the use of additives in the binder generated a stain-resistant effect in the void system. Many of the research results were put into practice on 19 test sections in total on the Federal Motorway A24 located 40 km northwest of Berlin. Besides the sections based on the findings of the project ‘Quiet Road Traffic 2’, other new developments of non porous noise reducing surface layers were constructed. Conventional Stone-Mastic-Asphalt and one and two layered PA were included in the test-concept to assess the acoustic effectiveness. The acoustic measurement showed a high level of noise reduction, but the expected additional effect due to the use of the Helmholtz-Resonators was not achieved. Additional research in the laboratory identified the composition of the PA as a cause. An exceptional high void content shifted the frequency position of the absorption maxima which made the resonator elements less effective than expected.


  • English

Media Info

  • Pagination: 9p
  • Serial:
    • Issue Number: A5EE-229

Subject/Index Terms

Filing Info

  • Accession Number: 01449014
  • Record Type: Publication
  • Source Agency: ARRB
  • Files: ATRI
  • Created Date: Oct 9 2012 1:19PM